The difference quotient is defined by
It gives the slope of the secant line passing through
and
. In the limit
, the difference quotient becomes the partial
derivative
The difference quotient is defined by
It gives the slope of the secant line passing through
and
. In the limit
, the difference quotient becomes the partial
derivative
Weisstein, Eric W. "Difference Quotient." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/DifferenceQuotient.html